Concrete finishing apparatus

ABSTRACT

A concrete compacting, screeding, and trowelling machine comprising a pair of rollers mounted in tandem by plates at the ends of the rollers, one or both rollers having powered internal vibrators, one or both rollers having a motor providing tractive effort for moving the machine, one of the rollers having a rotation preventor so that it can be dragged by the other roller as a screed, and one or both rollers having a petcock allowing the interior to be filled with fluid.

United States Patent [151 3,698,293 Wagner 5] Oct. 17, 1972 1 CONCRETE FINISHING APPARATUS 3,415,174 12/1968 Kaltenegger ..94/50 V [72] Inventor: Jacob Wagner R0 BOX 133 3,580,147 5/1971 Kaltenegger ..94/50 V New Castle New Castle 19720 2,025,703 12/1935 Bally ..94/48 [221 File March 2,1911 Primary Examiner-Jacob L. Nackenoff N0: Attorney-J0hn F. McClellan, Sr.

[57] ABSTRACT [52] US. Cl. ..94/50, 94/45 R [51] Int. Cl ..E0lc 19/28 A clgncrete z g and FY mac me COmPIISIIIg a pair 0 r0 ers moun e m an- [58] Field of Search ..94/50 V, 48, 45 dem y plates at the ends of the rollers, one or both [56] References Cited rollers having powered internal vibrators, one or both rollers having a motor providing tractive effort for UNi D STATES PATENTS moving the maching, one of tkhe gollersdhalgvinfl a rohtation preventor so t at it can e ragge y t e ot er 3'O48O89 8/ Kahenegger "94/50 v roller as a screed, and one or both rollers having a petn X cock allowing the interior to be filled with fluid. e n 1,665,054 4/1928 Carr; ..94/45 R 1 Claim, 5 Drawing Figures PATENTEDnm 11 I972 FIG?) INVENTOR JACOB C. WAGNER ATTORNEY CONCRETE FINISHING APPARATUS This invention relates generally to concretefinishing, and specifically to power tools used for the purpose of trowelling and screeding.

In the past, many powered means have been proposed and used for finishing concrete. They include scraper-trowels, flat-plate trowels having side-to-side oscillators to simulate hand trowelling, flat-plate trowels having vibrators, rotating flatplate trowels, rocking devices, and rotary trowels swinging plural cylindrical members about a central axis.

Some of these old-art devices, such as the scraper trowels, have been suitable for use with straight-edge guides alongside the pour to level the concrete as. well as to finish-trowel it.

A few of the old art devices have been extensible, providing means to trowel either a narrow swath or a broad swath.

Some of the known devices are adaptable to produce a cambered or crowned surface on the work, if desired, and a few can be used to impress a non-skid pattern into the surface simultaneously with another operation.

However, no powered trowel machine has been known which combines all the above advantages with additional advantages which will be disclosed below, including triple-use design for simultaneously screeding, compacting and trowelling, lightweight, economy, compactness, durability, ease of assembly and disassembly, and extreme versatility.

In a generalized embodiment the invention comprises a tandem-roller trowel-screed with means to rotate at least one tube for traction, means to brake one roller for screeding, and internal means to vibrate at least one roller for unique compaction of poured concrete being worked.

The above and other objects and advantages of this invention will be more readily understood on examination of the following description, including the drawings, in which:

FIG. 1 is a perspective view of an embodiment of the invention;

FIG. 2 is an end view of the FIG. 1 assembly;

FIG. 3 is a plan view in partial section of an embodiment of the invention;

FIG. 4 is a detail of an alternative drive mechanism; and

FIG. 5 is a detail of an alternative roller.

Now taking up the Figures in detail, FIG. 1 is a perspective view of an embodiment of this invention. Two tubular rollers, 12 and 14, are joined at each end by an end plate assembly, l6, 18. The end plates hold fixed tubular spindles 20, 22 (24, 26 not shown in this view).

The spindles mount the inner races of sealed antifriction bearings, and bearing caps 28, 30 (32,34 not shown in this view) affixed to the rollers mount the outer races of the bearings.

At least one of the rollers in the FIG. 1 embodiment is internally powered to propel the unit 10 by traction on the concrete being worked, and an electric power connection is provided for the purpose through detachable power-cord 32.

A cardinal feature of the invention, internal vibration means, represented diagrammatically by oscillatory solenoid-slug 32, is also powered through the electrical connection. The vibration compacts the surface of the concrete as the rollers advance, smoothing and finishing it and reducing the tractive effort required. This feature is explained at more length below. Either or both tubular rollers 12, 14, can be partially or entirely filled with water to increase weight. As shown, petcock 34 in the end of roller 14 affords means for supply and drain.

FIG. 2 illustrates a further feature of the FIG. I embodiment, the provision of means for braking one of the rollers to provide a rigid, true screed which can be pushed or dragged by tractive effort of the other roller. For the purpose, notches 36 are provided in one or more of the bearing caps as in 30, and rivet-and-slot sliding pawl means 38 on the inner side of the end plate is adapted to engage a notch and lock the roller. By use of this means coarse aggregate can be tumbled and smoothed. Additionally, a brush finish can be applied to the concrete surface C being worked, as required. When the unit 10 is run in the opposite direction, with the locked roll trailing, wear on the dragged roller is equalized through provision of a large number of notches, so that on the average one portion of the perimeter is abraded about as much as another if the notches are engaged at random. Either roller can be made the leading roller by simply pivoting one roller over the other to change position when the drive motor is reversed at the end of a run.

Aluminum tubing is the preferred material for the rollers, for lightness, although a thin casing of tough steel is useful in preventing wear. Teflon coatings on one or both rollers will retard sticking and provide a smoother trowelled surface, although care must be used to avoid unduly abrading the Teflon. Teflon is a trademark of the E. I. DuPont de Nemours Company, Inc.

FIG. 3 is a plan view in partial section of an embodiment 310 of the invention generally similar to that of FIGS. 1 and 2.

In the FIG. 3 embodiment rollers 312 and 314 are connected as previously described by end-plate assemblies 316 and 318.

Bearings are supplied as follows: each end plate assembly is clamped or welded to two inwardly turned non-rotating tubular spindles, shown at 320, 322, 324, 326. The spindles mount the inner races 338 of respective anti-friction bearings. Bearing caps 328, 300, 332, 334 mounted on the ends of the rollers secure the outer races 340 of the bearings to the ends of the rollers.

In this embodiment, at least one of the rollers as driven by an internally positioned, reversible electric gear motor 342, which is fixed to the roller and arranged to drive against a ring gear 343 fixed to the spindle.

The gear motor is supplied through an electric line 344, 345 and a socket 346 (better seen at 46 in FIG. 2) leading from the end plate to the gear motor through sliprings 348 on the spindle and sli-pring wipers 350, affixed to the roller. Because of varying conditions encountered in concrete finishing, the motor or motors are preferably adapted for external speed-control; they may be rheostated D. C. motors or SCR-controlled motors, for example.

Watertight bulkhead 356 protects the motor and slipring assembly when the roller is filled through petcock 334. Fluid tight bulkhead electrical fittings 358 penetrate the bulkhead.

The very important internal-vibration provision of this invention, which makes the entire invention so practical, is represented by solenoids 352, 354, screwed in place inside the roller at intervals along the length of the roller. Each solenoid is provided with a massive, short-travel slug 332, 333 arranged to reciprocate along a diameter of the roller, creating a heavy vibration to compact the concrete simultaneously with trowelling and screeding, each of the three operations favorably affecting the others, according to this invention. These solenoids are preferably of the sealed variety permitting operation under water when the rollers are filled or partially filled. Oscillation-control may be internal to each solenoid as by limit switch reversal, or may be externally supplied as by oscillator O. Other means such as motor driven eccentric weights may also be used for the purpose. The versatility of the operations of this invention can best be appreciated by consideration of the combinations afforded. One or both motors may be powered, providing any degree of traction required to surmount grades or coarse pours and to assure fine trowelling. One or both rollers may be filled to provide extra weight when required, both rollers may roll, or either the leading or the trailing roller may be used locked as a screed, and most importantly, reduce the surface being rolled, trowelled, or screeded.

It is particularly important also to note that the solenoids rotate with the roller, giving plural modes of operation on the work providing uniquely fast action and smooth finish, and that combining the vibration with a fluid mass (the water) does not dampen the action of the vibrators or create a rolling imbalance or preferential mode of vibration in the manner of solid weights.

Additionally, it should be noted that the interior of the unit is easily accessible at all times on disassembly since there are no cast-in-place or other solid weights in the device. I

The number of solenoids required varies by size and length of the rollers. Preferably, the rollers are easily extensible as by screwing on an additional length or lengths, 312, 312', FIG. 3.

Spacing between the rollers is not critical, but should be as close as practicable consistent with clearance between them for cleaning. The entire assembly is most compact and handy, with the end plates providing balanced grips for lifting.

In smaller sizes, as used for walkways and the like, the unit can easily be transported by two men and operated by one.

FIG. 4 illustrates further an advanced concept of the invention, that to obtain the best final finish, vibration must be internal and should be combined with self-traction of the unit, although the self-traction need not be internal. In FIG. 4, power to rotate roller 414 is supplied from an ordinary differential pulley assembly D operating a line L double-looped over a pulley 460 mounted on the roller. Pulley 460 is fixed on the end of cylindrical axle 462 which is rotatively fitted through the bore of the fixed spindle 422. The inner end of the axles bears an integral dog 464 which passes radially to the inner surface of the roller 414 and engages fixed dog-drive bosses 466, 468. When differential pulley D is rotated by power means (not shown) tractive effort is supplied to roller 414 by pulley D and slack is retrieved by pulley D". l

The net result [S that tractrve effort comes at least 1n part from the roller, thus matching rolling rate to rate of advance over the work and providing the smoothest finish obtainable by any machine for the purpose.

FIG. 5 illustrates an optional roller shape, 512, in this case concave in longitudinal section, as at 572, to provide a crowned surface on the work. Non-skid or ornamental patterns 570 may be provided in or on the surface to impart special finishes to the surface of the concrete, as may be desired.

Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. A concrete compacting, screeding, and trowelling machine comprising: first and second roller means, means for attaching the roller means together rotatively and in tandem, reversible means for self-tractively driving at least one of said attached roller means,

' means internal to at least one roller means for vibrating said roller means, and means for restraining rotation at one said roller means, thereby providing for the tractive effort of the other said roller means to drag said restrained roller means as a screed. 

1. A concrete compacting, screeding, and trowelling machine comprising: first and second roller means, means for attaching the roller means together rotatively and in tandem, reversible means for self-tractively driving at least one of said attached roller means, means internal to at least one roller means for vibrating saiD roller means, and means for restraining rotation of one said roller means, thereby providing for the tractive effort of the other said roller means to drag said restrained roller means as a screed. 